Vine Weevil Identification
Overview
Vine weevil identification depends on recognising two very different life stages:
- adult beetles feeding above ground
- larvae feeding below ground
The adults usually cause visible leaf-edge notching, while the larvae are responsible for most serious root and crown damage.
Adult vine weevil
Adult black vine weevils (Otiorhynchus sulcatus) are:
- approximately 8–10 mm long
- dark brown or black
- mottled in appearance
- flightless
- slow moving
- mainly active at night
- equipped with a short, broad snout
During the day they commonly hide:
- beneath pots
- under benches
- in cracks and joints
- beneath leaf litter
- inside dense crop canopies
- around old trays and containers
Adult feeding damage
Adult feeding typically produces:
- U-shaped notches around leaf margins
- scalloped leaf edges
- repeated bites around the outside of leaves
- cosmetic damage on ornamental crops
Adult feeding is usually less damaging than larval root feeding, but it is an important early warning sign that eggs and larvae may also be present.
Vine weevil larvae
Larvae are:
- creamy white
- legless
- curved into a C-shape
- brown-headed
- usually found in compost, substrate or around roots
Their size varies with development, but larger larvae are often easy to see when root balls are inspected.
Larval feeding damage
Larvae feed on:
- fine roots
- larger roots
- crowns
- stem bases
- root collars
Typical symptoms include:
- weak growth
- poor anchorage
- wilting
- stunting
- crown damage
- sudden collapse
- plant death during periods of stress
Plants may appear healthy until much of the root system has already been destroyed.
Where to inspect
Check:
- around the outer edge of root balls
- beneath the crown
- close to the compost surface
- beneath pots
- inside old substrate
- around weak or collapsing plants
Container-grown crops should be tipped from pots where practical and the root system examined carefully.
Adult or larval damage?
| Feature | Adult damage | Larval damage |
|---|---|---|
| Location | Leaves | Roots and crowns |
| Typical sign | U-shaped notches | Root loss and wilting |
| Time seen | Usually during active adult periods | Often autumn, winter and spring |
| Economic importance | Usually cosmetic | Potentially severe |
| Best inspection | Night torch checks | Root-ball inspection |
Often confused with
Chafer grubs
Chafer grubs may also be C-shaped and soil-dwelling, but they generally:
- have visible legs
- are often larger
- commonly occur in turf or open soil
- do not usually occur as densely in container root balls
Leatherjackets
Leatherjackets are:
- grey-brown
- legless
- elongated rather than strongly C-shaped
- usually associated with soil and turf
Swift moth larvae
Swift moth larvae can also feed around roots and crowns, but they are more elongated and caterpillar-like.
Slugs and caterpillars
Leaf-edge feeding may sometimes be confused with:
- slug grazing
- caterpillar chewing
- other adult weevils
Vine weevil damage is usually recognised by repeated, neat notches around the edge of leaves.
Confirmation checklist
Vine weevil is strongly indicated when several of the following occur together:
- U-shaped notches around leaf margins
- adult beetles found at night
- creamy, brown-headed, legless larvae in the root ball
- unexplained wilting despite adequate irrigation
- loss of fine roots
- crown or stem-base damage
- sudden plant collapse